Lens finishing and modifying machine

ABSTRACT

A machine for finishing lenses including a rotatable holder provided with controlled vacuum for holding and rotating the lens. An independently rotatable finishing tool is mounted for reciprocation along any of a number of arcuate paths of travel. The respective axes of rotation of the lens holder and the tool are selectively variable, and motor and cam means reciprocate the tool during various operations.

United States Patent 2,688,220 9/1954 Boutell Lawrence Littlelield I208 Stratiord Road, Kansas City, Mo. 64 l 1 3 Mar. 6, 1968 July 6, 1971 Inventor Appl. No. Filed Patented LENS FINISHING AND MODIFYING MACHINE 13 Claims, 8 Drawing Figs.

11.5. CI 51/55, 51/124 L, 51/235, 51/284 Int. Cl B24b 7/00.

B24b 9/00. B241: 47/00 FieldolSearch 51/31,95,

References Cited UNITED STATES PATENTS 2,634,557 4/1953 Seidner 51/331 1,639,012 8/1927 Tillyeret al 5l/l24LX 2,087,687 7/1937 Houchin 51/124 L X 2,291,000 7/1942 Simpson 51/124 L 3,134,208 5/1964 Richmond..... 51/235 3,274,737 9/1966 Rocher et a1. 51/235 X Primary Examinerlames L. Jones, Jr. Attorney-Don Bradley ABSTRACT: A machine for finishing lenses including a rotatable holder provided with controlled vacuum for holding and rotating the lens. An independently rotatable finishing tool is mounted for reciprocation along any of a number of arcuate paths of travel. The respective axes of rotation of the lens holder and the tool are selectively variable, and motor and cam means reciprocate the tool during various operations.

lLllEhlS ll llhllSll-lllNtG AND MGDlllFlr'llhlG MA ClillllhlE The invention relates to grinding and polishing machines and, more particularly, to a machine for performing the finishing operations for contact lenses or the like. Many of the steps of grinding and polishing blanks of lens material such as plexiglass or the like into finished optic lenses are conventionally carried out by hand. The steps of providing the movements of the grinding or polishing tool relative to the lens blank required to produce the optical characteristics desired in the finished lens are, however, often particularly well suited for mechanical equipment. The finishing operation may involve a number of repetitive movements of either the tool or the lens or both. These repetitive movements must usually be along a predetermined path of travel, which path may be carefully controlled in both direction and distance. Several different movements are often required to be carried out simultaneously.

Although the finishing of lenses can be done manually by skilled craftsmen, the expense of the manual finishing of the lenses is necessarily high and craftsmen having the requisite skill are few. Further, the duplicating of repetitive movements to attain the fine optical precision desired for contact lenses is only achieved by the use of machines for imparting these movements.

Machines capable of providing the wide range of movements necessary for performing a substantial part of the finishing of lenses have not heretofore been available. Consequently, much of the finishing has necessarily been performed manually.

Accordingly, it is the primary object of this invention to provide a lens finishing machine which is capable of providing a wide variety of relative movements between an unfinished lens and the finishing tool.

It is another important object of the invention to provide a finishing machine which is capable of providing accurately reproduced, repetitive finishing movements for precisely producing requisite optic characteristics in the finished lenses.

Still another object of the invention is to provide a machine wherein many of the manual steps of lens finishing are eliminated so that the operators carrying out the finishing operation need not possess the degree of skill heretofore required.

Another object of the invention is to provide a finishing machine wherein the lens and the tool are both simultaneously and independently rotated so that the relative speed and direction of rotation of thelens and tool may be selectively varied through a wide range. in the production of optical or quasi-optical surfaces such as are required in the peripheral portion of contact lenses, the relative speed of rotation of lens and tool are of prime importance in determining the shape and quality of finish of such surface.

A yet further object of the invention is the provision of means for controlling the negative air pressure used for holding an unfinished lens in its proper position so that the distortion of the lens caused by the force of the air pressure may be controlled and utilized in the finishing operation.

A still further important object of the invention is to provide a tool mount having its independent 'prime mover and means for moving the tool through a predetermined arc while the tool and the lens are rotated on their own independent axes by individually controlled drive means.

These and other very important objects of the invention will be further explained or will become apparent from the following specification and claims and from an inspection of the drawings.

In the drawings:

FIG. l is a fragmentary, detailed, partially schematic, vertical cross-sectional'view through a lens finishing machine embodying the principles of this invention, parts being broken away to show details of construction;

FIG. 2 is a top plan view taken along line 2-2 of FIG. 1;

FM}. 3 is a fragmentary, detailed, cross-sectional view taken along irregular line 3-3 of HG. l;

H6. 4 is a detailed, cross-sectional view taken along line tl-d of HG. l;

FlG. 5-5 is an enlarged, fragmentary perspective view ofa lens holder suitable for use with a lens finishing machine, the outer band being shown in cross section for clarity;

H6. 6 is an enlarged, fragmentary, side elevational view of a novel lapping tool for use with a lens finishing machine, parts being broken away and shown in cross section to reveal details of construction;

H6. "7 is a fragmentary, front elevational view of a modified embodiment of the lens finishing machine constructed pursuant to the principles of this invention, parts being broken away and shown in cross section to reveal details of construction; and

FlG. ll is an enlarged, fragmentary side elevational view of the pressure control valve and coupler used in machines embodying the concepts of this invention, parts being broken away and shown in cross section to reveal details of construction.

Referring initially to FlGS. 1-4, a lens finishing machine is broadly designated by the numeral and includes a frame 12 mounting a lensholcling assembly Ml and a toolholding assembly Mi. Assembly M includes an elongated, tubular shaft llfi rotatably and shiftably mounted in a bearing 20 which is secured to an upwardly extending wall 22 of a housing 24 forming a part of frame B2. A pulley 26 rigid to shaft 118 is connected by a flexible belt 23 to an elongated, generally cylindrical pulley 30 mounted on a prime mover in the nature of an electric motor 32. A coil spring 34 interposed between one end of bearing 20 and the proximal face of pulley 26 urges shaft llli to the left as illustrated in FIG. l. The left end of shaft ill} is concave to present a seat as complementally engaging the projecting nose portion of a connector 3h disposed in axial alignment with shaft w.

Connector 38 has an internal passage 40 aligned with the axial bore d2 of shaft id so that the passage and bore remain in fluid communication for a purpose to be described hereinafter as shaft in is rotated during operation of motor 32. The complementally engaging projection of connector 38 and seat 36 provides a sliding fluid seal at all times during operation of machine lit Connector 3% is closed at the end thereof remote from seat 3% and is an integral part of the piston 414 of a fluid piston and cylinder assembly as. The fluid chamber 4% of the cylinder 50 of assembly as is disposed in longitudinal alignment with the axial bore of shaft it; so that movement of piston 44 to the right as illustrated in the drawings under the influence of fluid pressure in chamber shifts shaft llti to the right for a pur pose to be more fully explained hereinafter. Conversely, shifting movement of piston M to the left, as illustrated in FIG. 1 of the drawings, permits spring 354 to move shaft 18 in a corresponding distance to the left. A plunger 52 mounted in a laterally extending collar 54 proximal the sliding path of travel of the piston M serves as a friction lock for holding the piston 414 at any selected predetermined position of shifting outwardly or inwardly with respect to cylinder 50. A handle 56 may be manually lifted in a slot 58 to move the abutting end of plunger 5?. out of physical engagement with piston and its integral connector E li. When manual control of the shifting movement of shaft lid is desired, such can be easily effected by means of a knob 59 and rod in secured to piston 44 and extending outwardly through a hole in the end of cylinder 50. During manual control of this movement, a valve 63 is opened to remove both positive and negative air pressure from cylinder 5th.

I The vacuum side of a source M of pressurized fluid such as a pump or the like is adapted to be coupled through a bleed or pressure regulating valve 62 to a vacuum line 64 which is in fluid communication with the central passage d0 of connector 38. The pressure side of source 60 is connected through a bleed or pressure regulating valve 66 to a pressure line 68 which is, in turn, connected in communication with the chamber did of cylinder 50 through a valve '70. A fluid control 72 for line 68 includes a body 74 having a pair of input ports 76 and 73 and a pair of output ports hi) and 82.

A sliding valve member 84 in control '72 is provided with passages 86 and 88 as illustrated generally in MG. 1 to selectively permit the coupling of pressure line 68 directly to valve 70 or to permit line 63 to be vented to atmosphere through passage 88 and port 36, while a portion 68a of line 68 connected to valve 70 is placed in fluid communication with vacuum line 64 through port 62, passage 88 and port 78. Manifestly, valves 62 and 66 and control 72 all form components of the controls which are accessible to the operator of machine at a control panel (not shown). Valves 62 and 66 are of a type which permits the operator to selectively vary the amounts of negative air pressure available in lines 64 and 68 respectively either by bleeding a portion of the airflow out of the air lines, or by other means. These valves are of types which are well known to those skilled in this art and need not be described in detail.

Referring now to FIG. 8, valve '70 includes a valve element 90 having a restricted passage 92 extending therethrough. Element 90 is normally held by a spring 91 against a seat at the end of passage 94) so that element 90 blocks passage 94. When air pressure is introduced into valve 711 from line 63a, the air pressure holds element 911 on its seat so that the air must flow through the restricted passage 92 as it flows into the chamber 48 of cylinder 50. On the other hand, when vacuum line 64 is connected to line portion 68a, the airflow proceeds in the opposite direction whereupon the flow moves element 90 off its seat to permit relatively unrestricted flow of the air through valve 70.

The end of shaft 1% proximal assembly 16 receives a tubular lens-holding element 96 which may be of rubber or similar material. An annular ridge 98on the outer surface of element 96 between the ends of the latter serves to position element 96 in telescoped relationship within the projecting end of shaft 18. The frictional engagement between element 96 and shaft 18 causes element 96 to be rotated and shifted with the latter. An axial bore Mill in element 96 is in alignment with bore 42 of shaft 18 and serves to place the outermost lens-holding end of element 96 in fluid communication with bore 62 for a purpose to be described later.

Referring now to the toolholding assembly 16, a motor 102 is mounted in a vertical position by a bracket 11M integral with a cylindrical, tubular projection 106 extending through a bearing 108 mounted in an aperture in frame 12. The axial bore of projection 106 rotatably mounts a vertically extending shaft 110 which is rigidly secured at its lowermost end to a U- shaped follower 112 best illustrated in FIG. 4. An eccentric 11d mounted on the shaft of motor 10?; moves through a path of travel between the spaced-apart legs of follower 112 to produce a corresponding rotation of shaft 116 in projection 106 along a reciprocating path of travel.

A crank 116 (FIGS. 1 and 3) rigidly secured at the uppermost end of shaft 1 11B is secured to an elongated arm 1 18 overlying frame 12. Crank 116 is secured to arm 118 by means ofa vertical pin 1211 in the outermost end of crank 1 16 and extending into one of a plurality of recesses 172 in the upper surface of arm 11%. The end of arm 118 proximal shaft 110 is bifurcated as illustrated best in FIG. 3. The other end of arm 1 18 is mounted on an elongated element 122 by bolt means 124 secured to element 122 and received in a longitudinally elongated slot 126 in arm 118. Element 122 is provided with an aperture which is received over projection 106 and element 122 is keyed to the latter for movement therewith.

An upwardly disposed standard 128 is integral with arm 1 18 and journals the shaft 130 of a rotatable drum 132 as illustrated in FIG. 1. Shaft 130 is, in turn, connected with a motor 134 through a flexible drive 136. Standard 128 terminates in a horizontally extending flange 138 which provides a bearing surface upon which is mounted a turret member 140 having a plurality of projections 142 which terminate in downwardly extending brackets 1 Turret member 140 is generally semicircular in shape (F16. 2) and is rotatable on a connecting bolt 146 so that any of the projections 142 as may be desired may be moved to a position in general alignment with shaft 18 of the lens holder.

Each of the brackets 144 may mount a tool assembly 148 as illustrated in FIGS. 1 and 2. Only one of the tools 148 has been illustrated for simplicity, but it will be recognized that a similar tool 148 could be installed on each of the brackets 1441. Tool assembly 148 includes a spindle 150 rotatably mounted in a bearing 152 received in an aperture 154 of bracket 144. A

. frustoconical projection 156 integral with spindle 150 is adapted to complementally and frictionally receive the recess of a lap or tool 158. The projecting surface of lap 158 may be provided with abrading, cutting or polishing means for performing a finishing operation on a lens held by element 96 as will be described hereinafter.

The end of spindle remote from projection 156 is provided with a drive wheel 160 having an O-ring 162 extending around its circumference as shown in FIG. 1. Manifestly, when turret member 140 is rotated to a position where the tool assembly 148 is in proper aligned relationship with shaft 18, O- ring 162 is also in frictional engagement with drum 132 so that motor 134 may be operated to drive tool assembly 148.

The end of element 122 remote from shaft 110 is provided with a knob 164 having a spring-loaded detent 166 which is engageable with any of a plurality of recesses 168 in the upper horizontal surface of frame 12 for locking element 22 in a predetermined angular position with respect to projection 106. As is illustrated in FIG. 3, the arcuate path of travel of the outermost end of element 122 in either direction from a position in direct alignment with shaft 18, is marked off in graduations with indicia 170 and the recesses 168 are spaced apart at uniform intervals.

In operation of machine 10, valve 62 is adjusted to the position to provide the desired amount of negative air pressure for holding an unfinished lens on the end of element 96 proximal lap 158. The end of element 96 may be of resilient 0r unyielding material as required by the operation to be performed and configured to complementally receive the lens thereon and may, therefore, be concave or convex, spherical, toric, aspheric, or of any irregular form, depending upon the shape of the particular surface to be mounted and opposing surface to be generated. The negative air pressure or vacuum holds the lens in position, and a spinning of the lens may be effected by operation of the motor 32. While spinning, the lens may be centered upon element Q6 by applying a low friction object at one or more circumferential positions. Manifestly, motor 32 is a type wherein both the speed and direction of rotation thereof may be controlled by the operator as desired.

Lap or tool 158 may also be rotated by the operator who can similarly control the speed and direction of rotation of motor 134. The operator may shift valve member 8 1 to the position illustrated in FIG. 1 which directs positive air pressure through lines 68 and 68a to valve 70. The air traveling through restricted passage 92 of valve 70 enters chamber 48 of cylinder 50 to slowly urge piston 44 to the right as illustrated in FIG. 1. This slowly moves shaft 18 and the lens mounted on the extreme end of element 96 toward the lap or grinding tool. The force which is used to urge shaft 18 and the unfinished lens toward the finishing tool is under the control of the operator who may adjust valve 66 for this purpose. Element 96, by virtue of its flexibility, adjusts itself so as to attain perfect alignment of the lens surface and the tool surface, thus resulting in a uniform action entirely around the circumference of the lens.

With the operation as has been described up to this point, the operator can perform an advantageous finished operation on the unfinished lens by virtue of the wide range of relative movement which is achievable because the shaft 18 and the lap 158 are independently and separately rotatable. Thus, the lens and lap may be rotated in opposite directions through any of a wide range of speeds. Opposite rotation has the advantage of maximizing relative speed and therefore faster removal of material, while at the same time minimizing absolute speed, thus reducing centrifugal force which causes undesirable flattening of the lens, changing of shape of lap, and throwing off of polishing compound; also, thus reducing dynamic imbalance which causes vibration and can result in chatter as lens and tool are brought into contact.

However, the finishing operation for lenses of this type often involves the movement of the tool along a reciprocating arcuate path of travel. Thus, the operator may energize motor 102 whereupon the eccentric and follower impart a reciprocating rotation to shaft 110. This rotation is, in turn, imparted through crank 116 to arm 118 whereupon the toolmounting assembly 16 is reciprocated about the upwardly extending projection 106. This pivot point is located very near the position of the operating surface of lap 158 and the resulting reciprocation of the latter moves the tool back and forth for performing the desired finishing operation on the spinning lens.

lt is contemplated that the assembly 16 should rotate through an arc of approximately zero to 90 under the influence of motor 102. Manifestly, the relationship of the crank 116 to arm 118 may be selectively varied for altering the amount of arcuate movement effected by tool 158 for each revolution of motor 102. In this respect, arm 118 may be provided with a number of holes 172 or the like to permit selective varying of the relationship of crank 1 16 to arm 118. Also, the splined connection of follower 112 to shaft 110 permits similar variation of the location of the limit within which the tool is reciprocated.

Additionally, the operator may swing element 122 and motor bracket 104 either to the right or to the left as indicated by the arrow in FIG. 3. This moves the initial alignment of assembly 16 with respect to the longitudinal axis of shaft 18. Thus, element 122 may be disposed in a zero position as shown in FIGS. 1 and 3 wherein the axis of rotation of lap or tool 158 is directly aligned with the axis of rotation of shaft 18. The are of movement of the tool across the lens effected by motor 102 will be on either or both sides of this zero line defined by the position of member 122. If, as is often desired, the operation is to be performed at an angle with respect to the principal axis of the lens, the operator may swing element 122 to any of the detent recesses 168. Such swinging moves the axis of rotation of tool 158 to a corresponding angular position with respect to the axis of rotation of shaft 18. The subsequent oscillation of assembly 16 then proceeds in an are on either or both sides of this zero reference point. Knob 164 is, of course, convenient for permitting manual swinging of element 122.

When it is desired to withdraw the lens from the finishing tool, the operator may simply shift valve member 84 to the left, as shown in FIG. 1. This connects vacuum line 64 to the line 680 so that piston 44 is withdrawn within cylinder 50.

of the entire force of the vacuum against piston 44 for a relatively rapid withdrawal and consequent shifting of shaft 18 to the. left as shown in FIG. 1 under the influence of spring 34. Since it isdesirable that pump not operate against an increased head of pressure, the pressure line 68 is vented to atmosphere through passage 88 when vacuum is applied to cylinder 50. The axial shifting of shaft 18 necessitates the relatively widepulley 30 so that belt 28 is in driven relationship withthe pulley throughout the range of shifting of the shaft. The vacuum in line 64, as well as the force of spring 34, serves to maintain a fluidtight connection at the sliding joint between the end of shaft 18 and connector 38.

Not to be overlooked at this juncture is the importance of the ability of the operator to control the negative fluid pressure within the shaft of bore 42. F IG. 5 illustrates a lens-holding element 196 which is particularly well suited for holding unfinished lenses in a manner so that fluid channels may be cut into the surface of the lens. Such channels to provide passages for fluid flow between the surface of the eyeball and the contact lens are desirable.

Element 196 provides means whereby the distortion caused to the lens by the forces of fluid pressure may be carefully and usefully controlled. Thus, element 196 has a concave end surface 197 communicating with the axial bore 200 of element 196. Inclined depressions 201 radiating from bore 200 serve to communicate a substantial portion. of the concave surface 197 with bore 200. Raised sections 203 are spaced uniformly around the periphery of element 196 and extend inwardly toward bore 200 but terminate in spaced relationship therefrom. in the example illustrated, element 196 is provided with four such raised sections 203.

Finally a circumscribing band 205 of rubber or similar material is disposed around element 196 with an edge thereof extending forwardly from surface 197 for frictionally engaging the outer peripheral rim of a lens to be finished thus controlling air leakage around the lens circumference. When negative fluid pressure is applied through shaft 18 to element 196, the pressure distorts the material of the unfinished lens so that it is drawn rather snugly against concave surface 197. The raised sections 203 however, hold the lens material so that the material is deformed as a result of the holding action of section 203 and the force of negative fluid pressure. The grinding of the exposed surface of the lens material necessarily causes a deeper cut into such exposed surface opposite the regions of the raised sections 203. When the lens is finally removed from the finishing machine, these deeper cuts provide the desired fluid passages in the surface of the contact lens. Likewise, lens-holding elements can be constructed to aid in deforming lenses by means of partial vacuum so as to produce toric and aspheric optical surfaces on the opposing faces.

A lap 258 is illustrated in FIG. 6 of the drawings and includes a cylindrical body 257 having a recessed, outermost end 259. The peripheral rim 261 of end 259 is convex as illustrated in the drawings. A layer 263 of sponge rubber or the like, approximately one-eighth inch thick is sandwiched between end 259 and a covering 265 of textile material which may be cotton flannel. Layer 263 and covering 265 are draped over end 261 and are frictionally retained in tightly stretched relationship across the recess of end 259 by an annular band 267 which is telescoped over the covering and the end of the lap. Manifestly, the lap may be provided with a recess for mounting on surface 156 of machine 10.

Lap 258 has been found to be particularly desirable for use with a finishing machine as illustrated in the drawings because the yieldably backed covering assumes the contour of the surface of the lens against which it is placed during the finishing operation. This lap can be used against concave lens surfaces and it is also equally useful against convex lens surfaces. Further, the lap has special utility in finishing operations on the beveled surfaces which are usually formed on the peripheral edges of the lens. Manifestly, a lapping compound is used in conventional manner.

Referring now to HO. 7 of the drawings, a modified actuator for shifting shaft 18 is illustrated. Thus, connector 238 has an aperture 239 extending transversely therethrough. Aperture 239 is tapered in two directions as: illustrated in the drawing to permit relative movement of an elongated arm 24]! which is received therethrough. Arm 241 is pivotally connected at one end to a shaft 243. A coil spring 245 is operably coupled with shaft 243 and arm 241 in such a manner that an operator may preset an indicator 247 on the control panel, and the relative positioning of indicator 247 determines the force of spring 245 against arm 241 to pivot the latter in a clockwise direction as viewed in FIG. 7. The outermost end ofarm 241 is provided with an eye 249 which is loosely received over the shank of an adjusting bolt 25! received in the outermost end of a connector 257 which is, in turn, pinned to the outermost end of the armature 255 of a solenoid 237.

In operation, solenoid 237 is deenergized to permit maximum extension of its armature 255 thus moving the head of bolt 251 to the right as illustrated in FIG. 7. Spring 245 may then exert a biasing force against arm 241 for moving connector 238 and consequently shaft 18 to the right. The amount of the force exerted by arm 241 is, of course, governed by the tension which has been preset in spring 245. This force can be carefully controlled to the conditions required for polishing or grinding a lens. When it is desired to retract shaft 18, it is merely necessary to energize solenoid 237 which retracts bolt 251 to the left as illustrated in FIG. 7. This moves arm 241 in a counterclockwise direction and shifts shaft 18 to the left.

Cylinder 50 may, of course, be provided with a valve 70 for admitting vacuum or pressurized fluid to effect the shifting of shaft 18 if desired. Further, line 64 maintains vacuum within shaft 18 for holding the lens on the lens holder as has been previously explained.

Having thus described the invention, what I claim as new and desire to be secured by Letters Patent is:

1. In a lens finishing machine of the type wherein an unfinished lens is adapted to be held for rotation, a rotatable finishing toolis adapted to engage said lens, and independently operable drive means is provided for rotating the lens and the tool, the improvement comprising:

a rotatable tubular shaft coupled with one of said drive means in axial alignment with and extending in the direction of said tool;

structure mounting said shaft against movement radially away from the axis of rotation of the tool;

an elongated, resilient, tubular element coupled with said shaft and radially flexible along a substantial length thereof relative to the axis of rotation of the shaft;

said element being generally concave to present a lens seat for holding the lens at the end thereof proximal the tool; and

vacuum means operably coupled with said shaft for applying continuous negative fluid pressure to the seat to hold the lens thereon during the finishing operation.

2. The invention of claim 1, wherein said holder includes an elongated shaft, said flexible element being coupled to the shaft in longitudinal extension thereof, said shaft having an axial bore communicating with the bore of the element, said vacuum means communicating with the shaft bore, the projecting element being free for flexing in any direction responsive to the forces imparted to the lens by said tool.

3. The invention of claim 2, wherein said vacuum means includes control means for selectively varying the negative air pressure at said seat, whereby the amount of deformation of said lens caused by said air pressure may be selectively controlled.

4. The invention of claim 2, wherein said vacuum means includes a conduit adapted to be coupled with a negative air pressure source, and a connector communicating with the conduit and disposed in sliding engagement with said shaft, said connector including structure communicating the bore with the conduit during rotation of the shaft relative to the connector.

5. The invention of claim 2, wherein said shaft is longitudinally shiftable, and wherein is included means engageable with said shaft for shifting the latter toward and away from said tool.

6. The invention of claim 5, wherein said shifting means includes a fluid piston and cylinder assembly, and positive and negative air pressure means operably coupled with said assembly for selectively advancing or retracting the piston of the assembly, said piston including means engageable with said shaft for shifting the latter toward the tool when the piston is advanced by said air pressure.

7. In a lens'finishing machine of the type including a rotatable lens holder adapted to hold an unfinished lens during a finishing operation; first drive means operably coupled with said holder for rotating the latter; a rotatable finishing tool adapted to engage said lens while the latter is on said holder respect to the axis of rotation of the tool; and power means operably coupled with said mounting means for reciprocating the tool on said path of travel, said mounting means including a frame, tool support structure,'and means pivotally mounting the support structure being manually swingable about said pivot for selectively varying the angular relationship between the axis of rotation of the tool and the axis of rotation of the lens holder, the improvement comprising:

said support structure including a standard, a turret member movably mounted on the standard, and a plurality of spaced-apart spindles rotatably mounted on said turret member, each spindle including a projection adapted to receive and hold a tool. 8. in a lens finishing machine of the type wherein is included a frame; a rotatable lens holder mounted on the frame; a rotatable finishing tool adapted to engage the lens when the latter is mounted on the holder; and means for rotating the holder and tool respectively, the improvement comprising:

tool support structure for carrying the tool and pivotally secured to the frame for reciprocation through an are about the axis of pivoting to the frame, said axis being perpendicular to the axis of rotation of the lens holder;

first tool aligning means for limited adjusting of the axis of arcuate movement of the structure;

second tool aligning means for adjusting the position of the first aligning means with respect to the axis of rotation of the tool holder; and I means for reciprocating said structure through said arc.

9. The invention of claim 8, wherein said second aligning means includes an elongated arm secured to the support structure and extending radially from said pivot, and lock means on the arm and frame respectively for releasably locking the arm in any selected position for disposing the tool at a corresponding angle with respect to said lens holder.

10. The invention of claim 9, wherein said lock means includes a detent carried by the arm and engageable with the frame.

ll. The invention of claim 8, wherein said support structure includes a standard, a turret member movably mounted on the standard, and a plurality of spaced-apart spindles rotatably mounted on said turret member, each spindle including a projection adapted to receive and hold a tool.

12. The invention of claim 9, wherein said first aligning means includes a crank having one leg rigidly secured to the tool support structure for pivoting about the pivotal axis of the latter, the other leg of the crank being pivotally secured to said elongated arm of the second aligning means in spaced relationship from the pivotal axis of the support structure; and means carried by the crank and arm respectively for selectively varying the point of pivotal connection between the crank and arm to vary the axis of reciprocation of the tool holder.

13. The invention of claim 12, wherein said rotatable finishing tool comprises:

a cylindrical body having a recess in one end thereof;

a covering of flexible material disposed over the recessed end of said body and extending around said end; and

a band received over the end of the body and said material for frictionally securing the latter to the body and over said recess. 

1. In a lens finishing machine of the type wherein an unfinished lens is adapted to be held for rotation, a rotatable finishing tool is adapted to engage said lens, and independently operable drive means is provided for rotating the lens and the tool, the improvement comprising: a rotatable tubular shaft coupled with one of said drive means in axial alignment with and extending in the direction of said tool; structure mounting said shaft against movement radially away from the axis of rotation of the tool; an elongated, resilient, tubular element coupled with said shaft and radially flexible along a substantial length thereof Relative to the axis of rotation of the shaft; said element being generally concave to present a lens seat for holding the lens at the end thereof proximal the tool; and vacuum means operably coupled with said shaft for applying continuous negative fluid pressure to the seat to hold the lens thereon during the finishing operation.
 2. The invention of claim 1, wherein said holder includes an elongated shaft, said flexible element being coupled to the shaft in longitudinal extension thereof, said shaft having an axial bore communicating with the bore of the element, said vacuum means communicating with the shaft bore, the projecting element being free for flexing in any direction responsive to the forces imparted to the lens by said tool.
 3. The invention of claim 2, wherein said vacuum means includes control means for selectively varying the negative air pressure at said seat, whereby the amount of deformation of said lens caused by said air pressure may be selectively controlled.
 4. The invention of claim 2, wherein said vacuum means includes a conduit adapted to be coupled with a negative air pressure source, and a connector communicating with the conduit and disposed in sliding engagement with said shaft, said connector including structure communicating the bore with the conduit during rotation of the shaft relative to the connector.
 5. The invention of claim 2, wherein said shaft is longitudinally shiftable, and wherein is included means engageable with said shaft for shifting the latter toward and away from said tool.
 6. The invention of claim 5, wherein said shifting means includes a fluid piston and cylinder assembly, and positive and negative air pressure means operably coupled with said assembly for selectively advancing or retracting the piston of the assembly, said piston including means engageable with said shaft for shifting the latter toward the tool when the piston is advanced by said air pressure.
 7. In a lens finishing machine of the type including a rotatable lens holder adapted to hold an unfinished lens during a finishing operation; first drive means operably coupled with said holder for rotating the latter; a rotatable finishing tool adapted to engage said lens while the latter is on said holder for imparting a finishing operation to the lens; second drive means independent of said first drive means for rotating said tool whereby different rotative movements may be imparted simultaneously to said lens and tool during the finishing operation; means mounting said tool for movement on a reciprocating path of travel about an axis disposed at an angle with respect to the axis of rotation of the tool; and power means operably coupled with said mounting means for reciprocating the tool on said path of travel, said mounting means including a frame, tool support structure, and means pivotally mounting the support structure being manually swingable about said pivot for selectively varying the angular relationship between the axis of rotation of the tool and the axis of rotation of the lens holder, the improvement comprising: said support structure including a standard, a turret member movably mounted on the standard, and a plurality of spaced-apart spindles rotatably mounted on said turret member, each spindle including a projection adapted to receive and hold a tool.
 8. In a lens finishing machine of the type wherein is included a frame; a rotatable lens holder mounted on the frame; a rotatable finishing tool adapted to engage the lens when the latter is mounted on the holder; and means for rotating the holder and tool respectively, the improvement comprising: tool support structure for carrying the tool and pivotally secured to the frame for reciprocation through an arc about the axis of pivoting to the frame, said axis being perpendicular to the axis of rotation of the lens holder; first tool aligning means for limited adjusting of the axis of arcuate movement of the structure; second tool aligning means For adjusting the position of the first aligning means with respect to the axis of rotation of the tool holder; and means for reciprocating said structure through said arc.
 9. The invention of claim 8, wherein said second aligning means includes an elongated arm secured to the support structure and extending radially from said pivot, and lock means on the arm and frame respectively for releasably locking the arm in any selected position for disposing the tool at a corresponding angle with respect to said lens holder.
 10. The invention of claim 9, wherein said lock means includes a detent carried by the arm and engageable with the frame.
 11. The invention of claim 8, wherein said support structure includes a standard, a turret member movably mounted on the standard, and a plurality of spaced-apart spindles rotatably mounted on said turret member, each spindle including a projection adapted to receive and hold a tool.
 12. The invention of claim 9, wherein said first aligning means includes a crank having one leg rigidly secured to the tool support structure for pivoting about the pivotal axis of the latter, the other leg of the crank being pivotally secured to said elongated arm of the second aligning means in spaced relationship from the pivotal axis of the support structure; and means carried by the crank and arm respectively for selectively varying the point of pivotal connection between the crank and arm to vary the axis of reciprocation of the tool holder.
 13. The invention of claim 12, wherein said rotatable finishing tool comprises: a cylindrical body having a recess in one end thereof; a covering of flexible material disposed over the recessed end of said body and extending around said end; and a band received over the end of the body and said material for frictionally securing the latter to the body and over said recess. 